Link Diagnosis is a free website tool that can analize backlinks and give you a report based on the pages they are based on. The report shows all manner of things like strength of link, page rank of the site, amount of outbound links on the page, age of the link and more.
We have found this tool addictive and invaluable in our web research and seo efforts. You can easily take a look at competiting sites and their link structure and see how they are being ranked higher than you. When doing search engine optimisation this is a great thing to know, as Google can use a lot of factors to determine how a page will get shown in results, having backlinks and good quality ones helps a lot.
We rate this tool a lot, and hope you will too. Check out Link Diagnosis here.